• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.245-246
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• 2012

The possibility that self-ignition can be generated near an obstacle is high in practical applications such as a hydrogen car. In this paper, experimental investigations were suggested to understand the effects of a wall on self-ignition phenomena through high-speed images. The results showed that the existence of a wall could not change the ignition phenomena itself irrespective of wall height and burst pressure. However, when a strong flame was induced in the tube, a wall could promote the flame stabilization.

• 로봇학회논문지
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• 제5권3호
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• pp.177-185
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• 2010

In this paper, a wall climbing robot, called LAVAR, is developed, which is using an impeller for adhering. The adhesion mechanism of the robot consists of an impeller and two-layered suction seals which provide sufficient adhesion force for the robot body on the non smooth vertical wall and horizontal ceiling. The robot uses two driving-wheels and one ball-caster to maneuver the wall surface. A suspension mechanism is also used to overcome the obstacles on the wall surface. For its design, the whole adhering mechanism is analyzed and the control system is built up based on this analysis. The performances of the robot are experimentally verified on the vertical and horizontal flat surfaces.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 가을 학술발표회 논문집
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• pp.315-321
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• 2001

Since 1984, block-type reinforced earth wall with geogrid reinforcement has been widely used for retaining wall applications till now in Korea. The use of geogrid as a reinforcement in the reinforced earth wall is steadily increased in an amount over 1,500,000㎡ in a year However, still need exists that some problems in design and construction practices should be made to review, Therefore, this paper reviewed reasonable criteria for selection of backfills, design details considering the effect of the upper soil slope on reinforced earth wall, horizontal displacement of facing block during compaction, and the damage of geogrid reinforcements on the edge part of facing block. Finally, alternative methods of measures on those problems are proposed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.141-157
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• 2008

Since 1984, block-type reinforced earth wall with geogrid reinforcement has been widely used for retaining wall applications till now in Korea. The use of geogrid as a reinforcement in the reinforced earth wall is steadily increased in an amount over $6,500,000m^2$ in a year. However, still need exists that some problems in design and construction practices should be made to review. Therefore, this paper reviewed current state and development items of geosynthetics-reinforced earth wall technology on design and construction point of view.

• Structural Engineering and Mechanics
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• 제32권2호
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• pp.213-233
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• 2009

In this paper the study of a reinforced concrete wall used as protection against accidental explosions in the petrochemical industry is presented. Many alternatives of accidental scenarios and sizes of the wall are analyzed and discussed. Two main types of events are considered, both related to vessel bursts: Pressure vessel bursts and BLEVE. The liberated energy from the explosion was calculated following procedures firmly established in the practice and the effects over the structures and the reinforced concrete wall were calculated by using a CFD tool. The results obtained show that the designed wall reduces the values of the peak overpressure and impulse and, as a result, the damage levels to be expected. It was also proved that a reinforced concrete wall can withstand the blast load for the considered events and levels of pressure and impulse, with minor damage and protect the buildings.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2631-2636
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• 2008

The most components and piping of the secondary side of domestic nuclear power plants were manufactured carbon-steel and low-alloy steel. Flow accelerated corrosion leads to wall thinning (metal loss) of carbon steel components and piping exposed to the flowing water or wet steam of high temperature, pressure, and velocity. The feedwater heaters of many nuclear power plants have recently experienced sever wall thinning damage, which increases as operating time progress. Several nuclear power plants in Korea have also experienced wall thinning damage in the shell wall around the impingement baffle. This paper describes the comparisons between the numerical analysis results using the FLUENT code and the experimental results based on down-scaled experimental facility. The experiments were performed based on several types of impingement baffle plates which are installed in low pressure feedwater heater.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.413-416
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• 2006

This paper presents the analytical results on the heat of hydration and induced thermal cracking of the wall elements in LiNAC that is a radioactive shield concrete structure. This wall elements measuring 1.2 m in thickness and 32 m in length tend to exhibit thermal cracking due to heat of hydration and high constraint effects caused by slab element located in the lower part of structure. In this analysis, four different construction stages were considered to find out the most effective concrete casting method in terms of thermal stress. Among the construction methods adopted in this analysis, the method of installation of construction connection measuring 1.2 m at the both side of wall elements was very effective way to control the thermal stress, resulting in increase thermal cracking index of wall elements in LiNAC structure. Finally, the wall elements in LiNAC structure was cast successfully according to the proposed construction method.

• Structural Engineering and Mechanics
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• 제5권2호
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• pp.167-175
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• 1997

A new seismic energy dissipation shear wall structure is proposed in this paper. The new shear wall is one with purposely built-in vertical slits within the wall panel, and various seismic energy dissipation devices are installed in the vertical slits so that the dynamic characteristics of the structure (for instance, lateral stiffness, ductility and fundamental period) can be controlled. In order to verify this concept, shaking table tests of two 10-story shear wall models were carried out, and the seismic behavior of the two models are studied by analyzing the test data and computing the nonlinear seismic response of the models.

• 대한조선학회논문집
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• 제54권4호
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• pp.321-328
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• 2017

In practice, cavitation phenomena occur in unbounded flows. However, the wall effect is unavoidable during experiments at a closed section such as a cavitation tunnel. Especially, supercavity generated behind a cavitator is relatively large and thick, so that geometric and dynamic characteristics of the cavity are affected by the tunnel wall. In order to apply experimental results into the unbounded flow field, physical correlations are necessary. In this paper, we proposed an image method based on a potential flow to simulate the wall effect. Considering two-dimensional wedge-shaped bodies, configurations and drag characteristics of the cavity were examined according to the distance ratio to the wall surface. The results were compared and verified with existing theoretical and experimental results.

• 한국지반신소재학회논문집
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• 제5권4호
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• pp.35-42
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• 2006

최대 높이가 29.5m인 고성토 보강토옹벽에 대한 시공 및 계측이 수행되었다. 이와 같이 높은 보강토옹벽에 대한 설계 및 시공 경험이 그다지 많지 않기 때문에, 본 현장에서는 철저한 설계 및 시공관리가 이루어졌다. FHWA 설계기준에 근거하여 본 현장 보강토옹벽의 내적 및 외적안정을 검토하였고, Bishop의 간편법을 이용하여 전반활동에 대한 안정성 해석을 수행하였다. 또한 시공관리 및 안정성 검토를 위한 일련의 현장계측을 수행하였다. 본 논문에서는 높이가 20m 이상이고, 2단으로 시공된 대표단면 2개소에 대한 계측결과를 분석하였다. 계측결과, 벽체 및 보강재의 변형이 매우 작게 측정되었으며, 벽체작용 수평토압 또한 미소한 것으로 나타났다. 따라서 높이가 20m이상으로 매우 높은 옹벽구조물에 있어서, 보강토옹벽공법이 성공적으로 적용될 수 있음을 확인하였고, 또한 시공관리가 잘 이루어질 경우 이같이 높은 보강토옹벽에 대하여 FHWA 설계기준이 매우 보수적인 안전측 결과를 보임을 알 수 있었다.